Nematicidal trifluorobutenes

ABSTRACT

The present invention relates to novel trifluorobutenes of the formula (I)                    
     wherein 
     R 1  represents hydrogen; halogen; alkyl that is unsubstituted or substituted with halogen, hydroxy, alkoxy, alkylthio, alkylcarbonyloxy, haloalkylcarbonyloxy, or cyano; alkylsulfonyloxy; or phenyl that is unsubstituted or substituted with halogen, alkyl, haloalkyl, alkoxy, alkylthio, alkylsulfonyl, haloalkoxy, haloalkylthio, phenyl, phenoxy, cyano, or nitro; 
     R 2  represents hydrogen; halogen; alkyl that is unsubstituted or substituted with alkoxy or halogen; or alkoxycarbonyl; and 
     n represents 0, 1 or 2, 
     with the proviso that if R 1  represents alkyl, then R 2  does not represent halogen. The invention also relates to processes for their preparation and their use as nematicides.

The present invention relates to novel trifluorobutenes, processes fortheir preparation and their use as a nematicidal agent.

Japanese Laid-open Patent Publication No. 85267/1990 describessubstituted azolethioethers which have insecticidal activity. U.S. Pat.No. 3,513,172 describes that some kinds of trifluorobutenyl compoundshave nematicidal activity and Japanese Laid-open Patent Publication(PCT) No. 500037/1988 describes that some kinds of polyhaloalkenecompounds have nematicidal activities. Further, WO 95/24403 describesthat 4,4-difluorobutenyl compounds have nematicidal activity.

There have now been found novel trifluorobutenes of formula (I)

wherein

R¹ represents hydrogen, halogen, or alkyl which may be unsubstituted orsubstituted with halogen, hydroxy, alkoxy, alkylthio, alkylcarbonyloxy,haloalkylcarbonyloxy or cyano, or represents alkylsulfonyloxy orrepresents phenyl which may be unsubstituted or substituted withhalogen, alkyl, haloalkyl, alkoxy, alkylthio, alkylsulfonyl, haloalkoxy,haloalkylthio, phenyl, phenoxy, cyano or nitro.

R² represents hydrogen, halogen, or alkyl which may be unsubstituted orsubstituted with alkoxy or halogen, or represents alkoxycarbonyl, and

n represents 0, 1 or 2.

provided that if R¹ represents alkyl, R² does not represent halogen.

In the definitions, the hydrocarbon chains, such as alkyl, are in eachcase straight-chain or branched. Substituents may be identical ordifferent.

Preferred substituents or preferred ranges of the radicals present inthe formulae listed above and below are defined below.

R¹ preferably represents hydrogen or halogen, or represents C₁₋₆ alkylwhich may be unsubstituted or substituted with halogen, hydroxy, C₁₋₃alkoxy, C₁₋₃ alkylthio, C₁₋₃ alkylcarbonyloxy,trifluoromethylcarbonyloxy or cyano, or represents C₁₋₄ alkylsulfonyloxyor represents phenyl which may be unsubstituted or substituted withhalogen, methyl, trifluoromethyl, methoxy, methylthio, methylsulfonyl,trifluoromethoxy, trifluoromethylthio, phenyl, phenoxy, cyano or nitro.

R² preferably represents hydrogen or halogen or represents C₁₋₆ alkylwhich may be unsubstituted or substituted with C₁₋₃ alkoxy or halogen,or represents C₁₋₄ alkoxycarbonyl.

n preferably represents 0 or 2.

R¹ particularly preferably represents hydrogen, fluoro, chloro or bromo,or represents C₁₋₄ alkyl which may be unsubstituted or substituted withfluoro, chloro, bromo, hydroxy, C₁₋₃ alkoxy, C₁₋₃ alkoxy, C₁₋₃alkylthio, C₁₋₃ alkylcarbonyloxy, trifluoromethylcarbonyloxy or cyano,or represents methylsulfonyloxy or ethylsulfonyloxy or represents phenylwhich may be unsubstituted or substituted with fluoro, chloro, bromo,methyl, trifluoromethyl, methoxy, methylthio, methylsulfonyl,trifluoromethoxy, trifluoromethylthio, phenyl, phenoxy, cyano or nitro.

R² particularly preferably represents hydrogen, fluoro, chloro or bromoor represents C₁₋₄ alkyl which may be unsubstituted or substituted withC₁₋₃ alkoxy or bromo or represents C₁₋₃ alkoxycarbonyl.

n particularly preferably represents 0.

The novel compounds of the above-mentioned formula (I) are obtained, forexample, by the following preparation processes a), b), c), d), e), f),g) or h).

Preparation Process a)

Compounds of the formula (I)

wherein

R¹ represents hydrogen, represents alkyl which may be substituted withhalogen, hydroxy, alkoxy, alkylthio, alkylcarbonyloxy,haloalkylcarbonyloxy or cyano or represents phenyl which may besubstituted with halogen, alkyl, haloalkyl, alkoxy, alkylthio,alkylsulfonyl, haloalkoxy, haloalkylthio, phenyl, phenoxy, cyano ornitro,

R² represents hydrogen or represents alkyl which may be substituted withalkoxy or halogen and

n represents 0

are obtained when compounds of the formula (II)

wherein

R^(1a) represents hydrogen, represents alkyl which may be substitutedwith halogen, hydroxy, alkoxy, alkylthio, alkylcarbonyloxy,haloalkylcarbonyloxy or cyano or represents phenyl which may besubstituted with halogen, alkyl, haloalkyl, alkoxy, alkylthio,alkylsulfonyl, haloalkoxy, haloalkylthio, phenyl, phenoxy, cyano ornitro,

R^(2a) represents hydrogen or represents alkyl which may be substitutedwith alkoxy or halogen and

n represents 0

are reacted with 4-bromo-1,1,2-trifluoro-1-butene in the presence ofinert solvents and if appropriate, in the presence of an acid binder.

Preparation Process b)

Compounds of the formula (I)

wherein

R¹ and R² are as defined above, and

n represents 1 or 2

are obtained when compounds of the formula (Ia)

wherein

R¹ and R² are as defined above

are oxidized in the presence of inert solvents.

Preparation Process c)

Compounds of the formula (I)

wherein

R¹ represents hydrogen or haloalkyl,

R² represents halogen, and

n represents 0

are obtained when compounds of the formula (Ib)

wherein

R^(1b) represents hydrogen or alkyl, and

R^(2b) represents hydrogen

are reacted with a halogenating agent in the presence of inert solvents.

Preparation Process d)

Compounds of the formula (I)

wherein

R¹ represents haloalkyl,

R² represents hydrogen or haloalkyl and

n represents 0

are obtained when compounds of the formula (Ic)

wherein

R^(1c) represents alkyl, and

R^(2c) represents hydrogen or alkyl,

are reacted with a halogenating agent in the presence of inert solvents.

Preparation Process e)

Compounds of the formula (I)

wherein

R¹ represents halogen,

R² represents hydrogen or alkyl and

n represents 0,

are obtained when compounds of the formula (III)

wherein

R^(2d) represents hydrogen or alkyl,

are reacted with a halogenating agent in the presence of inert solvents,and, if appropriate, in the presence of an organic base.

Preparation Process f)

Compounds of the formula (I)

wherein

R¹ represents alkylsulfonyloxy,

R² represents hydrogen or alkyl and

n represents 0

are obtained when compounds of the aforementioned formula (III) arereacted with compounds of the formula

R^(1d)SO₂Cl  (IV)

wherein

R^(1d) represents alkyl

in the presence of inert solvents, and if appropriate, in the presenceof an inorganic or organic base.

Preparation Process g)

Compounds of the formula (I)

wherein

R¹ represents alkyl,

R² represents alkoxycarbonyl and

n represents 0

are obtained when compounds of the formula (IV)

wherein

R^(1c) is as defined above, and

R³ represents alkyl,

are reacted with thiourea and the products are then reacted with4-bromo-1,1,2-trifluoro-1-butene in the presence of inert solvents.

Preparation Process h)

Compounds of the formula (I)

wherein

R¹ represents hydrogen,

R² represents alkoxyalkyl and

n represents 0

are obtained when compounds of the formula (Id)

wherein

R^(1e) represents hydrogen,

are reacted with compounds of the formula (VI)

R⁴—Br  (VI)

wherein

R⁴ represents alkoxyalkyl,

in the presence of inert solvents.

The compounds of the formula (I) of the present invention exhibit strongnematicidal activity and show good compatibility with various crops.

The compounds of the formula (I) according to the present inventionsurprisingly show a very outstanding nematicidal activity compared withthe compounds described in the aforementioned literature which aresimilar to the compounds of the present invention.

In the present specification “halogen” represents fluoro, chloro, bromoor iodo, preferably represents fluoro, chloro or bromo, and particularlypreferably represents chloro or bromo.

“Alkyl” and each alkyl part of “alkoxy”, “alkylthio”,“alkylcarbonyloxy”, “alkylsulfonyloxy” and “alkoxycarbonyl” represents astraight-chain or branched-chain alkyl such as methyl, ethyl, n- ori-propyl, n-, i-, s- or -t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl,preferably represents methyl, ethyl, n- or i-propyl, n-, i-, s-, ort-butyl, n-pentyl or n-hexyl and particularly preferably representsmethyl, ethyl, n- or i-propyl or n-, i-, s-, or t-butyl.

“Haloalkyl” and each haloalkyl part of “haloalkylcarbonyloxy”,“haloalkoxy” and “haloalkylthio” represents alkyl substituted with atleast one halogen, preferably represents C₁₋₄ alkyl substituted with oneor a plurality of halogen, and particularly preferably representsmethyl, ethyl or n- or i-propyl substituted with one or a plurality offluoro, chloro or bromo. “Haloalkyl” preferably represents chloromethyl,bromomethyl or trifluoromethyl.

Very particular emphasis is given to the group of the compounds of theformula (I) wherein

R¹ represents hydrogen, halogen, represents methyl, ethyl, n- ori-propyl, n-, i-, s- or t-butyl, n-pentyl or n-hexyl, each of which maybe substituted with halogen, hydroxy, methoxy, ethoxy, n- or i-propoxy,methylthio, ethylthio, n- or i-propylthio, methylcarbonyloxy,ethylcarbonyloxy, n- or i-propylcarbonyloxy, trifluoromethylcarbonyloxyor cyano, or represents methylsulfonyloxy, ethylsulfonyloxy, n- ori-propylsulfonyloxy, n-, i-, s- or t-butylsulfonyloxy or representsphenyl which may be substituted with halogen, methyl, trifluoromethyl,methoxy, methylthio, methylsulfonyl, trifluoromethoxy,trifluoromethylthio, phenyl, phenoxy, cyano or nitro,

R² represents hydrogen, halogen, methyl, ethyl, n- or i-propyl, n-, i-,s-, or t-butyl, n-pentyl or n-hexyl each of which may be substitutedwith methoxy, ethoxy, n- or i-propoxy or halogen or representsmethoxycarbonyl, ethoxycarbonyl, n- or i-propoxycarbonyl or n-, i-, s-,or t-butoxycarbonyl, and

n represents 0, 1 or 2.

However, if R¹ represents methyl, ethyl, n- or i-propyl, n-, i-, s- ort-butyl, n-pentyl or n-hexyl, R² does not represent halogen.

Very particular preference is furthermore given to the group ofcompounds of the formula (I), wherein

R¹ represents hydrogen, fluoro, chloro, bromo, represents methyl, ethyl,n- or i-propyl, n-, i-, s- or t-butyl, each of which may be substitutedwith fluoro, chloro, bromo, hydroxy, methoxy, ethoxy, n- or i-propoxy,methylthio, ethylthio, n- or i-propylthio, trifluoromethylcarbonyloxy orcyano, or represents methylsulfonyloxy or ethylsulfonyloxy, orrepresents phenyl which may be substituted with fluoro, chloro, bromo,methyl, trifluoromethyl, methoxy, methylthio, methylsulfonyl,trifluoromethoxy, trifluoromethylthio, phenyl, phenoxy, cyano or nitro,

R² represents hydrogen, fluoro, chloro, bromo, represents methyl, ethyl,n- or i-propyl or n-, i-, s- or t-butyl each of which may be substitutedwith methoxy, ethoxy, n- or i-propoxy or bromo or representsmethoxycarbonyl, ethoxycarbonyl or n- or i-propoxycarbonyl, and

n represents 0, 1 or 2.

However, if R¹ represents methyl, ethyl, n- or i-propyl or n-, i-, s- ort-butyl, R² does not represent fluoro, chloro or bromo.

The aforementioned preparation process a) can be represented by thefollowing reaction scheme if, for example, 2-mercaptooxazole and4-bromo-1,1,2-trifluoro-1-butene are used as starting materials.

The aforementioned preparation process b) can be represented by thefollowing reaction scheme, if, for example,2-(3,4,4-trifluoro-3-butenylthio)oxazole is used as starting materialand m-chloroperbenzoic acid is used as oxidizing agent.

The aforementioned preparation process c) can be represented by thefollowing reaction scheme, if, for example,2-(3,4,4-trifluoro-3-butenylthio)oxazole is used as starting materialand sulfuryl chloride is used as halogenating agent.

The aforementioned preparation process d) can be represented by thefollowing reaction scheme, if, for example,4-methyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole is used as startingmaterial and N-chlorosuccinimide is used as halogenating agent.

The aforementioned preparation process e) can be represented by thefollowing reaction scheme, if, for example,2-(3,4,4-trifluoro-3-butenylthio)oxazolidin-4-one is used as startingmaterial and phosphorus oxychloride is used as halogenating agent.

The aforementioned preparation process f) can be represented by thefollowing reaction scheme, if, for example,2-(3,4,4-trifluoro-3-butenylthio)oxazolidin-4-one and methanesulfonicchloride are used as starting materials.

The aforementioned preparation process g) can be represented by thefollowing reaction scheme, if, for example,2-chloro-5-methoxycarbonyl-4-methyloxazole, thiourea and4-bromo-1,1,2-trifluoro-1-butene are used as starting materials.

The aforementioned preparation process h) can be represented by thefollowing reaction scheme, if, for example,2-(3,4,4-trifluoro-3-butenylthio)oxazole and bromomethyl methyl etherare used as starting materials:

The compounds of the formula (II), used as starting material in theaforementioned preparation process a) include the known compoundsdescribed in the literature, for example in J. Org. Chem., (1988), 53(5), 1113-1114; Collect. Czech. Chem. Commun. (1983), 48 (12),3421-3425; Can. J. Chem., (1972), 50 (18), 3082-3083 etc.

As specific examples of the compounds of the formula (II) there can bementioned,

2-mercaptooxazole,

2-mercapto-4-methyloxazole,

4-ethyl-2-mercaptooxazole,

2-mercapto-5-methyloxazole,

5-ethyl-2-mercaptooxazole,

2-mercapto-5-n-propyloxazole,

2-mercapto-4-n-propyloxazole,

2-mercapto-4-iso-propyloxazole,

2-mercapto-4-tert-butyloxazole,

2-mercapto-4,5-dimethyloxazole,

2-mercapto-4-phenyloxazole and so on.

4-Bromo-1,1,2-trifluoro-1-butene, used as starting material in theaforementioned preparation process a), is a known compound described inthe document WO 86/07590.

The compounds of the formula (Ia), used as starting material in theaforementioned preparation process b), correspond to the compounds offormula (I) if n represents 0 and can be synthesized, for example,according to the aforementioned preparation process a).

As oxidizing agent used for the oxidation of the compounds of theabove-mentioned formula (Ia) in the preparation process b) there can bementioned those which are used usually in the field of organicchemistry, for example, hydrogen peroxide water, m-chloroperbenzoicacid, peracetic acid, perbenzoic acid, magnesium monoperoxyphthalate,potassium peroxymonosulfate and so on.

The compounds of the formula (Ib) and the formula (Ic), used as startingmaterials in the aforementioned preparation process c) and preparationd), respectively, are generally described by the formula (I) of thepresent invention, wherein n represents 0. They can be synthesized, forexample, according to the aforementioned preparation process a).

As halogenating agent, which can be reacted with the compounds of theformula (Ib) and the formula (Ic) in the preparation process c) andpreparation d), respectively, there can be mentioned those which areused usually in the field of organic chemistry, for example, sulfurylchloride, N-chlorosuccinimide, N-bromosuccinimide, trichloroisocyanuricacid, potassium fluoride, chlorine gas, bromine, iodine and so on.

The compounds of the formula (III) used as starting materials in theaforementioned preparation process e) and preparation f) are novelcompounds which were not described in the literature before. They can beprepared, for example, according to the following process i).

Preparation Process i)

Compounds of the formula (III) are obtained when compounds of theformula (VII)

wherein

R^(2d) is as defined before,

are reacted with 4-bromo-1,1,2-trifluoro-1-butene in the presence of aninert solvent, and, if appropriate, in the presence of an acid binder.

The compounds of the above-mentioned formula (VII) include knowncompounds and can be synthesized, for example, according to the processdescribed in Ukrain. Khim. Zhur., 16, 545-551 (1950).

As specific examples of the compounds of the aforementioned formula(III) there can be mentioned, for example,

2-(3,4,4-trifluoro-3-butenylthio)oxazolidin-4-one,

5-methyl-2-(3,4,4-trifluoro-3-butenylthio)oxazolidin-4-one and so on.

As halogenating agents, which can be reacted with the compounds of theaforementioned formula (III) in the preparation process e) there can bementioned phosphorus oxychloride, phosphorus oxybromide, phosphoruspentachloride and so on.

The compounds of the aforementioned formula (IV), which are needed inthe preparation process f), are well known in the field of organicchemistry. Specific examples which can be mentioned are methanesulfonicchloride, ethanesulfonic chloride etc.

The compounds of the formula (V) used as starting materials in theaforementioned preparation process g), are known compounds and can beprepared, for example, according to the process described in document WO95/24403.

Specific examples of the compounds of the aforementioned formula (V)which can be mentioned are 2-chloro-5-methoxycarbonyl-4-methyloxazole,2-chloro-5-ethoxycarbonyl-4-methyloxazole etc.

The compounds of the formula (Id) used as starting materials in thepreparation process h) are generally described by the formula (I) of thepresent invention and can be synthesized, for example, according to theaforementioned preparation process a). Further, the compounds of theformula (VI), which are needed in the preparation process h), are wellknown compounds in the field of organic chemistry. Specific exampleswhich can be mentioned are bromomethyl methyl ether, bromomethyl ethylether etc.

The reaction of the preparation process a) can be conducted in thepresence of an adequate diluent. Examples of the diluents which can beused here are aliphatic, alicyclic and aromatic hydrocarbons, such ashexane, cyclohexane, petroleum ether, ligroine, benzene, toluene orxylene; ethers, such as, diethyl ether, methyl ethyl ether, di-isopropylether, dibutyl ether, propylene oxide, dioxane or tetrahydrofuran;ketones, such as acetone, methyl ethyl ketone or methyl isobutyl ketone;nitriles, such as acetonitrile, propionitrile or acrylonitrile; acidamides, such as, dimethylformamide, dimethylacetamide orN-methylpyrrolidone.

The reaction of the preparation process (a) can be conducted in thepresence of an acid binder. Acid binders which can be used are, forexample, hydroxides, carbonates and alcoholates etc. of alkali metals,tertiary amines, such as, triethylamine, diethylaniline, pyridine,4-dimethylaminopyridine, 1,4-diazabicyclo[2,2,2]octane (DABCO) or1,8-diazabicyclo[5,4,0]undec-7-ene (DBU).

The reaction of the preparation process a) can be conducted in asubstantially wide range of temperature. In general, the processes arecarried out at temperatures between 0° C. and 150° C., preferablybetween 20° C. and 100° C. Although said reaction is generally carriedout under normal pressure, it can be optionally carried out underelevated pressure or under reduced pressure.

When carrying out the preparation process a), the compounds of thecorresponding formula (I) can be obtained by reacting, for example,0.7-1.5 moles of 4-bromo-1,1,2-trifluoro-1-butene with 1 mole of thecompounds of the formula (II) in a diluent, for example, acetonitrile inthe presence of 1-1.3 moles of an acid binder, for example, potassiumcarbonate, under reflux by heating.

Among the compounds of the formula (I) of the present invention whichcan be prepared by the preparation process a), the compounds the formula(I) wherein R¹ represents hydroxymethyl, alkoxymethyl, halogenomethyl,alkylcarbonyloxy, alkylthiomethyl or cyanomethyl, R² represents hydrogenand n represents 0, can be also synthesized according to other processesdescribed in Synthesis Examples 10-14 below.

The reaction of the preparation process b) can be carried out in thepresence of an adequate diluent. Examples of the diluents which can beused are aliphatic, alicyclic and aromatic hydrocarbons which may beoptionally chlorinated, such as, hexane, cyclohexane, petroleum ether,ligroine, benzene, toluene, xylene, methylene chloride, chloroform,carbon tetrachloride, ethylene chloride or chlorobenzene; ethers, suchas, diethyl ether, methyl ethyl ether, di-isopropyl ether, dibutylether, propylene oxide, dioxane or tetrahydrofuran; alcohols, such as,methanol, ethanol, isopropanol, butanol or ethylene glycol; esters, suchas, ethyl acetate or amyl acetate; acid amides, such as,dimethylformamide, dimethylacetamide or N-methylpyrrolidone; carboxylicacids, such as, formic acid or acetic acid.

The reaction of the preparation process b) can be conducted in asubstantially wide range of temperatures. In general, the processes arecarried out at temperatures between −20° C. and 100° C., preferablybetween 0° C. and 80° C. Although said reaction is generally carried outunder normal pressure, it can be optionally carried out under elevatedpressure or under reduced pressure.

When carrying out the preparation process b), the compounds of thecorresponding formula (I) can be obtained by reacting, for example,0.8-3 moles of m-chloroperbenzoic acid with 1 mole of the compounds ofthe formula (Ia) in a diluent, for example, methylene chloride, at roomtemperature.

The reaction of the preparation processes c) and d) can be carried outin the presence of an adequate diluent. Examples of the diluents whichcan be used are aliphatic, alicyclic and aromatic hydrocarbons which maybe optionally chlorinated, such as, hexane, cyclohexane, petroleumether, ligroine, benzene, toluene, xylene, methylene chloride,chloroform, carbon tetrachloride, ethylene chloride or chlorobenzene;ethers, such as, diethyl ether, methyl ethyl ether, di-isopropyl ether,dibutyl ether, propylene oxide, dioxane or tetrahydrofuran; acid amides,such as, dimethylformamide, dimethylacetamide or N-methylpyrrolidone;sulfones and sulfoxides, such as, dimethyl sulfoxide or sulfolane.

The reaction of the preparation processes c) and d) can be conducted ina substantially wide range of temperatures. In general, the processesare carried out at temperatures between −20° C. and 200° C., preferablybetween 0° C. and 150° C. Although said reaction is generally carriedout under normal pressure, it can be optionally carried out underelevated pressure or under reduced pressure.

When carrying out the preparation processes c) and d), the compounds ofthe corresponding formula (I) can be obtained by reacting e.g. 1-4 molesof N-chlorosuccinimide with 1 mole of the compounds of the formula (Ib)in a diluent, such as, carbon tetrachloride, under reflux by heating.

The reaction of the preparation process e) can be carried out in thepresence of an adequate diluent. Examples of the diluent which can beused are hydrocarbons including halogenated hydrocarbons, ethers,nitrites and acid amides according to the list of diluents mentioned inthe aforementioned preparation process b).

The reaction of the preparation process (e) can be carried out in thepresence of an organic base. Organic bases which can be used are, forexample, triethylamine, 1,1,4,4-tetramethylethylenediamine (TMEDA),N,N-dimethylaniline or pyridine.

The reaction of the preparation process e) can be carried out in asubstantially wide range of temperatures. In general, the processes arecarried out at temperatures between 0° C. and 200° C., preferablybetween 20° C. and 120° C. Although said reaction is generally carriedout under normal pressure, it can be optionally carried out underelevated pressure or under reduced pressure.

When carrying out the preparation process e), the compounds of thecorresponding formula (I) can be obtained by reacting, for example, 1-5moles of a halogenating agent to 1 mole of the compounds of the formula(III) in the presence of pyridine.

The reaction of the preparation process f) can be carried out in thepresence of an adequate diluent. Examples of the diluents which can beused are the same diluents as mentioned in the aforementionedpreparation process e) and, in addition, there can be mentionedalkylsulfonyl chlorides, for example, methanesulfonyl chloride,ethanesulfonyl chloride or isopropylsulfonyl chloride.

Further, the reaction of the preparation process (f) can be carried outin the presence of inorganic bases and organic bases. Organic baseswhich can be used are the same ones as exemplified in the aforementionedpreparation process e). Inorganic bases which can be used are, forexample, sodium carbonate or potassium carbonate.

The reaction of the preparation process f) can be carried out in asubstantially wide range of temperature. In general, the processes arecarried out at temperatures between −20° C. and 150° C., preferablybetween 0° C. and 130° C. Although said reaction is generally carriedout under normal pressure, it can be optionally carried out underelevated pressure or under reduced pressure.

When carrying out the preparation process f), the compounds of thecorresponding formula (I) can be obtained by reacting, for example, 1-3moles of a compound of the formula (IV) to 1 mole of the compounds ofthe formula (III) with an organic base, for example triethylamine, inthe presence of a diluent, for example tetrahydrofuran.

The reaction of the preparation process g) can be carried out in thepresence of an adequate diluent. Diluents which can be used are the samediluents as mentioned in the aforementioned preparation process a) and,in addition, alcohols, for example, methanol, ethanol or isopropanol.

The reaction of the preparation process g) can be carried out in asubstantially wide range of temperature. In general, the processes arecarried out at temperatures between 0° C. and 150° C., preferablybetween 20° C. and 120° C. Although said reaction is generally carriedout under normal pressure, it can be optionally carried out underelevated pressure or under reduced pressure.

When carrying out the preparation process g), the compounds of thecorresponding formula (I) can be obtained by reacting, for example,1-1.5 moles of thiourea to 1 mole of the compounds of the formula (V) ina diluent, for example, ethanol and then reacting with 1-1.5 moles of4-bromo-1,1,2-trifluoro-1-butene.

The reaction of the preparation process h) can be carried out in thepresence of an adequate diluent. Diluents which can be used are, forexample, the ethers exemplified before.

The reaction of the preparation process h) can be carried out in asubstantially wide range of temperature. In general, the processes arecarried out at temperatures between 100° C. and 150° C., preferablybetween −78° C. and 100° C. Although said reaction is generally carriedout under normal pressure, it can be optionally carried out underelevated pressure or under reduced pressure.

When carrying out the preparation process h), the compounds of thecorresponding formula (I) can be obtained by reacting, for example,1-1.5 moles of the compounds of the formula (VI) to 1 mole of thecompound of the formula (Id) in a diluent, for example, diethyl ether,in the presence of n-butyl lithium.

The reaction of the preparation process i) can be carried out in thepresence of an adequate diluent. Diluents which can be used are the samediluents as mentioned in the aforementioned preparation process a).

The reaction of the preparation process (i) can be carried out in thepresence of the same acid binder as mentioned in the aforementionedpreparation process a).

The reaction of the preparation process (i) can be carried out byapplying the same reaction temperatures and pressures mentioned in theaforementioned preparation process a).

When carrying out the preparation process i), the compounds of thecorresponding formula (III) can be obtained by reacting, for example,0.7-1.5 moles of 4-bromo-1,1,2-trifluoro-1-butene to 1 mole of thecompounds of the formula (VII) in a diluent, for example,tetrahydrofuran, in the presence of 1-1.3 moles of triethylamine.

The compounds of the formula (I) of the present invention show a strongability to control nematodes. They can, therefore, be efficiently usedas nematicidal agents.

Furthermore, the compounds of the formula (I) of the present inventionshow no phytotoxicity against crops and at the same time exhibit theability to specifically control harmful nematodes.

Examples of nematodes against which the active compounds of the formula(I) of the present invention can be applied are, for example,Pratylenchus spp., Globodera rostochiensis Wollenweber, Heterodera spp.,such as, Heterodera glycines Ichinohe, Meloidogyne spp., Aphelenchoidesbasseyi Christie, Bursaphelenchus Xylophilis, Radopholus similis,Ditylenchus dipsaci, Tylenchulus semipenetrans etc. However, thenematodes which can be controlled by said compounds are not limited tothe above list.

The active compounds of the present invention can also be used asmixtures with other active compounds, such as, insecticides,bactericides, miticides, fungicides etc. in the form of theircommercially useful formulation or in the application form prepared fromthose formulations. Possible components for the mixtures areinsecticides, for example organophosphorus agents, carbamate agents,carboxylate type chemicals, chlorinated hydrocarbon type chemicals orchloronicotinyl type chemicals, insecticidal substances produced bymicrobes.

Further, the active compounds of the present invention can also be usedas mixtures with synergists in such formulations and application formsas can be mentioned as commercially useful. A synergist itself must notbe active, but enhances the action of the active compound.

The content of the active compounds of the present invention in acommercially useful formulation or application form can be varied in awide range. The application concentration of the active compounds of theformula (I) of the present invention can be in the range of generally0.000001-100% by weight, preferably 0.00001-1% by weight.

The active compounds of the present invention can be converted into thecustomary formulations, such as, solutions, emulsions, wettable powders,water dispersible granules, suspensions, powders, foaming agents,pastes, granules, active compound-impregnated natural and syntheticsubstances, microcapsules, fumigants etc.

These formulations can be prepared according to per se known methods,for example by mixing the active compounds with extenders, namely liquidsolvents, liquefied gas and/or solid diluents or carriers, andoptionally with surfactants, namely emulsifiers and/or dispersantsand/or foam formers. When water is used as extender, it is also possibleto use, for example, organic solvents as auxiliary solvents.

Liquid diluents or carriers which can be used are, for example, aromatichydrocarbons, such as, xylene, toluene or alkylnaphthalene, chlorinatedaromatic or chlorinated aliphatic hydrocarbons, such as, chlorobenzenes,ethylene chlorides or methylene chloride, aliphatic hydrocarbons such ascyclohexane or paraffins, such as mineral oil fractions, alcohols, suchas, butanol, glycols and their ethers or esters, ketones, such as,acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone,strongly polar solvents, such as, dimethylformamide or dimethylsulphoxide, water and so on.

Liquefied gas diluents or carriers are liquefied substances which aregases at normal temperature and pressure. Examples are aerosolpropellants such as butane, propane, nitrogen gas, carbon dioxide andhalogenated hydrocarbons.

Solid diluents which can be used are, for example, ground naturalminerals such as kaolin, clay, talc, chalk, quartz, attapulgite,montmorillonite or diatomaceous earth, ground synthetic minerals such ashighly dispersed silicic acid, alumina or silicates and so on.

Solid carriers for granules which can be used are for, example, crushedand fractionated rocks, such as, calcite, marble, pumice, sepiolite ordolomite synthetic granules of inorganic and organic meals, particles oforganic materials, such as, sawdust, coconut shells, maize cobs ortobacco stalks and so on.

Emulsifiers and/or foam-forming agents which can be used are, forexample, nonionic and anionic emulsifiers, such as, polyoxyethylenefatty acid esters or polyoxyethylene fatty acid alcohol ethers, such as,alkylaryl polyglycol ethers, alkylsulphonates, alkylsulphates orarylsulphonates, albumin hydrolysis products and so on.

Dispersants include, for example, ligninsulphite waste liquor and methylcellulose.

Tackifiers may also be used in formulations, such as, powders, granulesor emulsions. Tackifiers which can be used are, for example,carboxymethyl cellulose, natural and synthetic polymers, such as, gumarabic, polyvinyl alcohol or polyvinyl acetate.

Colorants may also be used. Colorants which can be used are, forexample, inorganic pigments such as iron oxide, titanium oxide orPrussian Blue, organic dyestuffs, such as, alizarin dyestuffs, azodyestuffs or metal phthalocyanine dyestuffs, and further tracenutrients, such as, salts of metals such as iron, manganese, boron,copper, cobalt, molybdenum or zinc.

Said formulations generally comprise the aforementioned activecomponents in a range of between 0.1-95% by weight, preferably between0.5-90% by weight.

The preparation and use of the compounds of the present invention willbe described more specifically in the following examples. However, thepresent invention should not be restricted to them in any way. “Parts”means “parts by weight” unless specified.

EXAMPLES Preparation Examples Example 1

7.5 g of 4-bromo-1,1,2-trifluoro-1-butene and 7.0 g of potassiumcarbonate were added to 50 ml of acetonitrile, 3.8 g of2-mercaptooxazole, and refluxed for 5 hours by heating. After coolingthe reaction mixture to room temperature, solid substance was filteredby suction and the filtrate was distilled off under reduced pressure.The residue was purified by column chromatography (eluent:hexane:dichloromethane=1:1) to obtain 6.5 g of2-(3,4,4-trifluoro-3-butenylthio)oxazole as colorless oil (yield 82.7%,n²⁰ _(D)=1.4631).

Example 2

1.0 g of 2-(3,4,4-trifluoro-3-butenylthio)oxazole and 1.5 g ofm-chloroperbenzoic acid (purity about 70%) were added to 50 ml ofdichloromethane and stirred at room temperature for 20 hours. Thereaction mixture was washed with 50 ml of 1N aqueous solution of sodiumhydroxide and dried with magnesium sulfate. After the solvent wasdistilled off under reduced pressure, the residue was purified by columnchromatography (eluent: ethyl acetate:dichloromethane=1:4) to obtain 1.0g of 2-(3,4,4-trifluoro-3-butenylsulfinyl)oxazole as colorless oil(yield 92.9%, n²⁰ _(D)=1.4820).

Example 3

1.0 g of 2-(3,4,4-trifluoro-3-butenylthio)oxazole and 3.0 g ofm-chloroperbenzoic acid (purity about 70%) were added to 50 ml ofdichloromethane and stirred at room temperature for 20 hours. Thereaction mixture was washed with 50 ml of 1N aqueous solution of sodiumhydroxide and dried with magnesium sulfate. After the solvent wasdistilled off under reduced pressure, the residue was purified by columnchromatography (eluent: dichloromethane) to obtain 0.8 g of2-(3,4,4-trifluoro-3-butenylsulfonyl)oxazole as colorless oil (yield69.4%, n²⁰ _(D)=1.4705).

Example 4

4.0 g of 2-(3,4,4-trifluoro-3-butenylthio)oxazole was added to 40 ml ofDMF (dehydrated) to which a mixture of 10 ml of chloroform and 2.6 g ofsulfuryl chloride was added dropwise at 50 in 1 hour. After the reactionmixture was stirred at 50° C. for 3 hours, a mixture of 5 ml ofchloroform and 0.8 g of sulfuryl chloride was further added dropwise in15 minutes. After stirring at 50° C. for 15 hours, the reaction mixturewas cooled to room temperature, poured into 200 ml of ice water andextracted with 100 ml of hexane. The aqueous layer was neutralized with1N aqueous solution of sodium hydroxide and further extracted with 100ml of hexane. The extracted hexane layers were put together, washed with200 ml of saturated common salt water and dried with magnesium sulfate.After the solvent was distilled off under reduced pressure, the residuewas purified by column chromatography (eluent:hexane:dichloromethane=1:1) to obtain 2.4 g of5-chloro-2-(3,4,4-trifluoro-3-butenylthio)oxazole as colorless oil(yield 51.5%, n²⁰ _(D)=1.4830).

Example 5

2.2 g of 4-methyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole was dissolvedin 40 ml of dichloromethane and 3.4 g of N-bromosuccinimide were addedand stirred at room temperature for 5 hours. After the solvent wasdistilled off under reduced pressure, the residue was purified by columnchromatography (eluent: hexane:ethyl acetate=93:7) to obtain 2.4 g of5-bromo-4-bromomethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole (yield63%). n²⁰ _(D)=1.4963.

Example 6

2 g of phosphorus oxychloride were added dropwise to a mixture of 1 g of2-(3,4,4-trifluoro-3-butenylthio)oxazolidin-4-one and 0.35 g of pyridineunder ice cooling and stirred at 70-80° C. for 3 hours. After additionof ice water to the reaction mixture and stirring for 30 minutes, themixture was extractred with dichloromethane. The extracted layer waswashed with water, dried with anhydrous sodium sulfate and the solventwas distilled off under reduced pressure. The residue was purified bycolumn chromatography (eluent: dichloromethane) to obtain 0.7 g of4-chloro-2-(3,4,4-trifluoro-3-butenylthio)oxazole (yield 65%). n²⁰_(D)=1.4813.

Example 7

1 g of 2-(3,4,4-trifluoro-3-butenylthio)oxazolidin-4-one and 0.9 g oftriethylamine were dissloved in 30 ml of tetrahydrofuran, to which 0.56g of methanesulfonic chloride was added dropwise under ice cooling andstirred at 50° C. for 8 hours. After distilling off the solvent underreduced pressure, the residue was dissolved in ether. After washing with1N hydrochloric acid and water, it was dried with anhydrous sodiumsulfate and the solvent was distilled off under reduced pressure. Theresidue was purified by column chromatography (eluent:hexane:dichloromethane=1:1) to obtain 0.25 g of4-methylsulfonyloxy-2-(3,4,4-trifluoro-3-butenylthio)oxazole (yield19%). n²⁰ _(D)=1.4830.

Example 8

2.1 g of 2-chloro-5-methoxycarbonyl-4-methyloxazole and 1.1 g ofthiourea were dissloved in 55 ml of ethanol and refluxed for 8 hours.After cooling, the solvent was distilled off under reduced pressure. Theresidue was dissolved in 55 ml of acetone, to which 2.5 g of4-bromo-1,1,2-trifluoro-1-butene and 2.4 g of potassium carbonate wereadded, stirred at room temperature for 18 hours and the solvent wasdistilled off under reduced pressure. After addition of 50 ml of waterto the residue and extraction with ether, the ether layer was washedwith water and dried with anhydrous sodium sulfate. After the solventwas distilled off under reduced pressure, the residue was treated bysilica gel column chromatography to obtain 3.1 g of5-methoxycarbonyl-4-methyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole. n²⁰_(D)=1.4972.

Example 9

10.40 ml of n-butyl lithium (1.6 M n-hexane solution) were slowly addeddropwise to a solution of 3.14 g of2-(3,4,4-trifluoro-3-butenylthio)oxazole in 40 ml of ether at −70° C.After stirring for 1 hour, a solution of 2.06 g bromomethyl methyl etherin 10 ml ether was added dropwise. After bringing the mixture back toroom temperature and stirring for 1 hour, 50 ml of saturated solution ofammonium chloride was added to separate it into an ether layer and anaqueous layer. The aqueous layer was further extracted with ether andtogether with the separated ether layer it was washed with a saturatedsodium chloride water and dried with anhydrous magnesium sulfate. Afterthe solvent was distilled off under reduced pressure, the residue wastreated by column chromatography to obtain 0.5 g of5-methoxymethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole (yield 13%).n²⁰ _(D)=1.4705.

Example 10

7.5 g of 3,8-dioxa-1,6-diazaspiro[4,4]nona-1,6-diene-2,7-dithiol, 7.5 gof 4-bromo-1,1,2-trifluoro-1-butene and 7.0 g of potassium carbonatewere added to 200 ml of acetonitrile and refluxed for 5 hours. Thereaction mixture was cooled to room temperature and filtered by succtionand the filtrate was distilled under reduced pressure. The residue waspurified by column chromatography (eluent: ethylacetate:dichloromethane=1:4) to obtain 7.0 g of4-hydroxymethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole as colorlessoil (yield 74.2%). n²⁰ _(D)=1.4910.

Example 11

A solution of 2.7 g of4-hydroxymethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole in 50 ml oftetrahydrofuran (dehydrated) was added dropwise to a suspension of 0.5 gNaH (purity about 60%) in 20 ml of tetrahydrofuran (dehydrated) at 0° C.After stirring the mixture at room temperature for 1 hour, a solution of2.0 g of methyl iodide in 20 ml of tetrahydrofuran (dehydrated) wasadded at 0° C. and further stirred at room temperature for 1 hour. Thereaction mixture was poured into a mixed solution of 200 g ice and 2Nhydrochloric acid. After extraction with 100 ml of dichloromethane, thesolution was washed with water and dried with anhydrous magnesiumsulfate. After the solvent was distilled off under reduced pressure, theresidue was purified by column chromatography (eluent: dichloromethane)to obtain 1.5 g of4-methoxymethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole as colorlessoil (yield 52.5%). n²⁰ _(D)=1.4710.

Example 12

6.8 g of 4-hydroxymethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole and2.5 g of pyridine were dissolved in 30 ml of chloroform, to which asolution of 5.0 g of thionyl chloride in 10 ml of chloroform was addeddropwise at 0° C. After the addition the mixture was refluxed for 10hours. After cooling to room temperature, the solvent was distilledunder reduced pressure. The residue was purified by columnchromatography (eluent: hexane:dichloromethane=2:1) to obtain 5.7 g of4-chloromethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole as colorless oil(yield 77.8%). n²⁰ _(D)=1.4933.

Example 13

1.2 g of ⁴-chloromethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole, 0.5 gof sodium thiomethoxide and 0.1 g of sodium iodide were added to 20 mlof dimethylformamide (hehydrated) and stirred at 80° C. for 10 hours.After cooling, 200 ml of water were added to the reaction mixture andextracted with 100 ml of diethyl ether twice. The extracted diethylether layers were put together, washed with 200 ml of water, dried withmagnesium sulfate and the solvent was distilled off under reducedpressure. The residue was purified by column chromatography (eluent:hexane:dichloromethane=2:1) to obtain 0.3 g of4-methylthiomethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole as colorlessoil (yield 23.9%). n²⁰ _(D)=1.5099.

Example 14

3 g of 4-hydroxymethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole and 1.5g of triethylamine were dissolved in 50 ml of dichloromethane, to whicha solution of 1 g of acetyl chloride in 20 ml of dichloromethane wasadded dropwise under ice cooling. After stirring at room temperature for8 hours, the mixture was washed with water and dried with anhydroussodium sulfate. After the solvent was distilled off under reducedpressure, the residue was treated by column chromatography to obtain 2.7g of 4-acetoxymethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole (yield76.5%). n²⁰ _(D)=1.4752.

Example 15

1.2 g of 4-chloromethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole, 1 g ofpotassium cyanide, 0.1 g of 18-crown-6-ether and 0.1 g of sodium iodidewere added to 20 ml of dimethylformamide (dehydrated) and stirred at100° C. for 20 hours. After cooling, 200 ml of water was added to thereaction mixture and extracted with 100 ml of diethyl ether twice. Theextracted diethyl ether layers were put together, washed with 200 ml ofwater, dried with magnesium sulfate and the solvent was distilled offunder reduced pressure. The residue was purified by columnchromatography (eluent: hexane:dichloromethane=2:1) to obtain 0.3 g of4-cyanomethyl-2-(3,4,4-trifluoro-3-butenylthio)oxazole as colorless oil(yield 15.6%). n²⁰ _(D)=1.4844.

The compounds of the formula (I) of the present invention, synthesizedby the similar manner to the processes described in the above-mentionedSynthesis Examples 1-9 are shown in Table 1. And the compounds ofSynthesis Examples 1-15 are also shown in Table 1.

In Table 1, Me represents methyl, Et represents ethyl, n-Pr representsn-propyl, i-Pr represents isopropyl, n-Bu represents n-butyl, t-Burepresents t-butyl, n-Pen represents n-pentyl, n-Hexrepresents n-hexyland Ph represents phenyl.

TABLE 1

Compound No. R¹ R² n mp or n²⁰ _(D) 1 H H 0 1.4631 2 H H 1 1.4820 3 H H2 1.4705 4 H Cl 0 1.4830 5 H Cl 1 1.4980 6 H Cl 2 1.4805 7 H Br 0 1.50298 H Br 1 1.5110 9 H Br 2 10 H I 0 11 H I 1 12 H I 2 13 H Me 0 14 H Me 115 H Et 0 16 Me H 0 1.4665 17 Me H 1 1.4788 18 Me H 2 1.4641 19 Me Me 01.4702 20 Me Me 1 1.4825 21 Me Me 2 1.4683 22 Me Et 0 23 Me n-Pr 0 24 EtH 0 25 Et H 1 26 Et H 2 27 n-Pr H 0 28 n-Pr H 1 29 i-Pr H 0 30 n-Bu H 031 n-Bu H 2 32 t-Bu H 0 33 n-Pen H 0 34 ClCH₂ H 0 1.4933 35 ClCH₂ Cl 036 ClCH₂ Cl 1 37 ClCH₂ Cl 2 38 BrCH₂ H 0 39 BrCH₂ Br 0 1.4963 40 BrCH₂Br 2 1.4745 41 BrCH₂ BrCH₂ 0 42 BrCH₂ BrCH₂ 1 43 BrCH₂ BrCH₂ 2 44 BrCH₂Me 0 45 Me BrCH₂ 0 46 H MeOCH₂ 0 1.4705 47 H MeOCH₂ 1 1.4812 48 H MeOCH₂2 49 H EtOCH₂ 0 50 H EtOCH₂ 2 51 H i-PrOCH₂ 0 52 Cl H 0 1.4813 53 Cl H 154 Cl H 2 1.4785 55 Cl Me 0 56 Cl Me 1 57 Cl Me 2 58 Cl Et 0 59 Cl Et 160 Cl Er 2 61 Cl n-Pr 0 62 Cl i-Pr 0 63 Cl Cl 0 64 Br H 0 1.5012 65 Br H1 1.5226 66 Br H 2 67 I H 0 68 I H 2 69 Me MeOOC 0 1.4972 70 Me MeOOC 171 Me MeOOC 2 1.4710 72 Me EtOOC 0 73 Me EtOOC 1 74 Me n-PrOOC 0 75HOCH₂ H 0 1.4910 76 HOCH₂ H 1 77 HOCH₂ H 2 78 MeOCH₂ H 0 1.4710 79MeOCH₂ H 1 80 MeOCH₂ H 2 1.4700 81 EtOCH₂ H 0 82 EtOCH₂ H 1 83 EtOCH₂ H2 84 n-PrOCH₂ H 0 85 i-PrOCH₂ H 0 86 MeSCH₂ H 0 1.5099 87 MeSCH₂ H 1 88MeSCH₂ H 2 89 EtSCH₂ H 0 90 EtSCH₂ H 1 91 EtSCH₂ H 2 92 n-PrSCH₂ H 0 93i-PrSCH₂ H 0 94 MeCOOCH₂ H 0 1.4752 95 MeCOOCH₂ H 1 96 MeCOOCH₂ H 21.4765 97 EtCOOCH₂ H 0 98 EtCOOCH₂ H 1 99 EtCOOCH₂ H 2 100 n-PrCOOCH₂ H0 101 i-PrCOOCH₂ H 0 102 CF₃COOCH₂ H 0 1.4430 103 CF₃COOCH₂ H 1 104CF₃COOCH₂ H 2 1.4388 105 NCCH₂ H 0 1.4844 106 NCCH₂ H 1 107 NCCH₂ H 2108 Ph H 0 1.5455 109 Ph H 1 110 Ph H 2 1.5368 111 2-F-Ph H 0 1124-Cl-Ph H 0 113 4-Cl-Ph H 2 114 3-Me-Ph H 0 115 4-CF₃-Ph H 0 1164-MeO-Ph H 0 117 4-MeS-Ph H 0 118 4-MeSO₂-Ph H 2 119 4-CF₃O-Ph H 0 1204-CF₃S-Ph H 0 121 4-Ph-Ph H 0 122 4-PhO-Ph H 0 123 4-CN-Ph H 0 1244-NO₂-Ph H 0 125 3,4-diMe-Ph H 0 126 2,4-diCl-Ph H 0 127 MeSO₂O H 01.4830 128 MeSO₂O H 1 129 MeSO₂O H 2 130 EtSO₂O H 0 131 EtSO₂O H 2 132n-Hex H 0 133 H n-Pr 0 134 H iso-Pr 0 135 H iso-Pr 2 136 H n-Bu 0 137 Hn-Pen 0 138 H n-Hex 0

Preparation Examples (Starting Materials) Example (A)

16.5 g of potassium thiocyanate were added to 400 ml of ethanol, towhich 15 ml of concentrated hydrochloric acid was added little by littleunder cooling and stirred for 1 hour. An ethanol solution of thiocyanicacid was obtained by filtration of the reaction mixture. In anotherflask 300 ml of water and 19.0 g of dihydroxyfumaric acid were stirredat 60° C. for 1 hour to obtain an aqueous solution of glycolaldehydethrough decarboxylation. The solutions were mixed and refluxed for 15hours. After the reaction was finished, the solvent was distilled offunder reduced pressure and the residue was purified by columnchromatography (eluent: ethyl acetate:dichloromethane=1:9) to obtain 4 gof 2-mercaptooxazole as white crystals (yield 30.8%). m.p. 149-150° C.

Example (B)

32 ml of 35% formalin, 46 ml of water and 165 ml of concentratedhydrochloric acid were added to a mixture of 65 g of potassium cyanideand 97 g of potassium thiocyanate, and stirred at room temperature forone night. After filtering the deposited crystals, the filtrate wasrefluxed for 2 hours and alkalized with an aqueous solution of sodiumhydroxide. After washing with ether, the solution was acidified withconcentrated hydrochloric acid and extracted with ethyl acetate. Theethyl acetate layer was dried with anhydrous sodium sulfate and thesolvent was distilled off under reduced pressure to obtain 26.1 g of4-oxazolidinon-2-thione (yield 18%). {J. Med. Chem. 37(2), 322-8(1994)}.

Example (C)

1 g of 4-oxazolidinon-2-thione and 1.8 g of triethylamine were dissolvedin 43 ml of tetrahydrofuran, to which 1.9 g of4-bromo-1,1,2-trifloro-1-butene and 0.2 g of 4-dimethylaminopyridinewere added and refluxed for 4 hours. After cooling and distilling offthe solvent under reduced pressure, ether and water were added andstirred vigorously. After washing the ether layer with aqueous solutionof sodium hydroxide and dried with anhydrous sodium sulfate, the solventwas distilled off under reduced pressure. The residue was treated bycolumn chromatography (eluent: dichloromethane) to obtain 1 g of2-(3,4,4-trifluoro-3-butenylthio)oxalin-4-one (yield 52%). n²⁰_(D)=1.4964.

Example (D)

40 ml of concentrated hydrochloric acid was added little by little to asuspension of 35.0 g of potassium thiocyanate in 300 ml of ethanol,under ice cooling and sirred for 1 hour. By filtering the depositedcrystals, an ethanol solution of thiocyanic acid was obtained. Asolution of 15.0 g of dihydroxyacetone in 100 ml of ethanol was added tothe above-mentioned ethanol solution of thiocyanic acid and refluxed for15 hours. After finishing the reaction, the solvent was distilled offunder reduced pressure and the residue was washed with 100 ml ofdichloromethane and filtered. The filtered crystals were recrystallizedfrom ethanol to obtain 28.4 g of3,8-dioxa-1,6-diazaspiro[4,4]nona-1,6-diene-2,7-dithiol (yield 89.6%).mp. 200-202° C.

Example (E)

150 g of methyl 2-chloroacetoacetate and 180 g of urea were dissolved in600 ml of methanol and refluxed for 36 hours. After cooling, thedeposited crystals were filtered, suspended in 2N sodium hydroxidesolution and extracted with ethyl acetate. After washing with water anddrying with anhydrous sodium sulfate, the solvent was distilled offunder reduced pressure. The residue was recrystallized from acetonitrileto obtain 10 g of 2-amino-5-methoxycarbonyl-4-methyloxazole. mp.199-201° C. (point of decomposition).

Example (F)

To a suspension of 4.84 g of cupric chloride and 3.4 g of tert-butylnitrite in 150 ml of acetonitrile, 4.7 g of2-amino-5-methoxycarbonyl-4-methyloxazole was added at below 10° C.under argon stream and stirred at room temperature for 2 hours. Aftertreatment with 2N hydrochloric acid, the mixture was extracted withether, washed with water, dried with anhydrous sodium sulfate and thesolvent was distilled off under reduced pressure. The residue wastreated by silica gel column chromatography to obtain 2.1 g of2-chloro-5-methoxycarbonyl-4-methyloxazole. mp. 69-71° C.

Use Examples Example 1 Test Against Meloidogyne spp. (Soil Pot Test)

Preparation of Test Agent:

1 Part of the active compound is impregnated to 99 parts of pumice tomake fine granules.

Test Method:

A compound of the formula (I) was added to the soil contaminated byMeloidogyne incognita so that the chemical concentration would be 10 ppmand homogeneously mixed by stirring. A pot ({fraction (1/5000)} are) wasfilled with the soil. About 20 seeds of tomato (variety: Kurihara) weresown per pot. After cultivation in a greenhouse for 4 weeks, they werecarefully pulled out not to damage the roots and the root knot index andthe controlling effect were determined as follows.

Degree of damage

0: No knot was formed

1: A few knots were formed

2: Knots were formed to a medium extent

3: Knots were formed to an intense extent

4: Knots were formed to the most intense extent (corresponds tonon-treatment).${{Root}\quad {knot}\quad {index}} = {\frac{\sum\left( {{degree}\quad {of}\quad {damage} \times {number}\quad {of}\quad {individuals}} \right)}{{Total}\quad {number}\quad {of}\quad {tested}\quad {individuals} \times 4} \times 100}$${{Controlling}\quad {effect}} = {\frac{\begin{pmatrix}\left( {{{Root}\quad {knot}\quad {index}\quad {at}\quad {non}\text{-}{treated}\quad {area}} -} \right. \\\left. {{Root}\quad {knot}\quad {index}\quad {at}\quad {treated}\quad {area}} \right)\end{pmatrix}}{\left( {{Root}\quad {knot}\quad {index}\quad {at}\quad {non}\text{-}{treated}\quad {area}} \right)} \times 100}$

Evaluation of the ability of the tested compounds to control thenematodes was done according to the values obtained for the controllingeffect and with the following standards.

a: Controlling effect 100-71%

b: Controlling effect 70-50%

c: Controlling effect less than 50%

d: Controlling effect 0%

In this test, the compounds of the Preparation Examples 1, 2, 3, 4, 5,6, 8, 16, 17, 18, 19, 20, 21, 39, 46, 52, 54, 64, 65, 71, 75, 78, 80,86, 96, 108, 110 and 127 showed controlling effect a.

Formulation Examples Example a) (Granule)

To a mixture of 10 parts of a compound of the present invention (e.g.Example. 1), 30 parts of bentonite (montmorillonite), 58 parts of talcand 2 parts of ligninsulfonate salt, 25 parts of water are added, wellkneaded, made into granules of 10-40 mesh with the help of an extrusiongranulator and dried at 40-50° C. to obtain granules.

Example b) (Granule)

95 parts of clay mineral particles having particle diameter distributionof 0.2-2 mm are put into a rotary mixer. While rotating it, 5 parts of acompound according to the present invention (e.g Example 2) are sprayedtogether with a liquid diluent, wetted uniformly and dried at 40-50° C.to obtain granules.

Example c (Emulsifiable Concentrate)

30 parts of a compound according to the present invention (e.g. Example3), 55 parts of xylene, 8 parts of polyoxyethylene alkyl phenyl etherand 7 parts of calcium alkylbenzenesulfonate are mixed and stirred toobtain an emulsifiable concentrate.

Example d) (Wettable Powder)

15 parts of a compound according to the present invention (e.g. Example1), 80 parts of a mixture of white carbon (hydrous amorphous siliconoxide fine powders) and powder clay (1:5), 2 parts of sodiumalkylbenzenesulfonate and 3 parts of sodiumalkylnaphthalenesulfonate-formalin-condensate are crushed and mixed toobtain a wettable powder.

What is claimed is:
 1. A compound of the formula (I)

wherein R¹ represents hydrogen; halogen; alkyl that is unsubstituted orsubstituted with halogen, hydroxy, alkoxy, alkylthio, alkylcarbonyloxy,haloalkylcarbonyloxy, or cyano; or alkylsulfonyloxy; R² representshydrogen; halogen; alkyl that is unsubstituted or substituted withalkoxy or halogen; or alkoxycarbonyl; and n represents 0, 1, or 2, withthe proviso that if R¹ represents alkyl, then R² does not representhalogen.
 2. A compound of the formula (I) according to claim 1 whereinR¹ represents hydrogen; halogen; C₁₋₆ alkyl that is unsubstituted orsubstituted with halogen hydroxy, C₁₋₃ alkoxy, C₁₋₃ alkylthio, C₁₋₃alkylcarbonyloxy, trifluoromethylcarbonyloxy or cyano; or C₁₋₄alkylsulfonyloxy; R² represents hydrogen; halogen; C₁₋₆ alkyl that isunsubstituted or substituted with C₁₋₃ alkoxy or halogen; or C₁₋₄alkoxycarbonyl; and n represents 0 or
 2. 3. A compound of the formula(I) according to claim 1 wherein R¹ represents hydrogen; fluoro, chloro,or bromo; C₁₋₄ alkyl that is unsubstituted or substituted with fluoro,chloro, bromo, hydroxy, C₁₋₃ alkoxy, C₁₋₃ alkylthio, C₁₋₃alkylcarbonyloxy, trifluoromethylcarbonyloxy or cyano; ormethylsulfonyloxy or ethylsulfonyloxy; R² represents hydrogen; fluoro,chloro, or bromo; C₁₋₄ alkyl that is unsubstituted or substituted withC₁₋₃ alkoxy or bromo; or C₁₋₃ alkoxycarbonyl; and n represents
 0. 4. Acompound of the formula (I) according to claim 1 wherein R¹ representshydrogen; halogen; methyl, ethyl, n- or i-propyl, n-, i-, s-, ort-butyl, n-pentyl, or n-hexyl, each of which is optionally substitutedwith halogen, hydroxy, methoxy, ethoxy, n- or i-propoxy, methylthio,ethylthio, n- or i-propylthio, methylcarbonyloxy, ethylcarbonyloxy, n-or i-propylcarbonyloxy, trifluoromethylcarbonyloxy, or cyano;methylsulfonyloxy, ethylsulfonyloxy, n- or i-propylsulfonyloxy, or n-,i-, s-, or t-butylsulfonyloxy; R² represents hydrogen; halogen; methyl,ethyl, n-or i-propyl, n-, i-, s-, or t-butyl, n-pentyl, or n-hexyl, eachof which is optionally substituted with methoxy, ethoxy, n- ori-propoxy, or halogen; or methoxycarbonyl, ethoxycarbonyl, n- or-propoxycarbonyl or n-, i-, s-, or t-butoxycarbonyl; and n represents 0,1 or
 2. 5. A compound of the formula (I) according to claim 1 wherein R¹represents hydrogen; fluoro, chloro, or bromo; methyl, ethyl, n- ori-propyl, or n-, i-, s-, or t-butyl, each of which is optionallysubstituted with fluoro, chloro, bromo, hydroxy, methoxy, ethoxy, n- ori-propoxy, methylthio, ethylthio, n- or i-propylthio,trifluoromethylcarbonyloxy, or cyano; or methylsulfonyloxy orethylsulfonyloxy; R² represents hydrogen; fluoro, chloro, or bromo;methyl, ethyl, n- or i-propyl, or n-, i-, s-, or t-butyl, each of whichis optionally substituted with methoxy, ethoxy, n- or i-propoxy, orbromo; or methoxycarbonyl, ethoxycarbonyl, or n- or i-propoxycarbonyl;and n represents 0, 1 or
 2. 6. A process for preparing a compound offormula (I) according to claim 1 comprising (a) for compounds of formula(I) in which R¹ represents hydrogen; or alkyl that is optionallysubstituted with halogen, hydroxy, alkoxy, alkylthio, alkylcarbonyloxy,haloalkyl-carbonyloxy, or cyano; R² represents hydrogen or alkyl that isoptionally substituted with alkoxy or halogen; and n represents 0,reacting a compound of the formula (II)

wherein R^(1a) represents hydrogen; or alkyl that is optionallysubstituted with halogen, hydroxy, alkoxy, alkylthio, alkylcarbonyloxy,haloalkyl-carbonyloxy, or cyano; R^(2a) represents hydrogen or alkylthat is optionally substituted with alkoxy or halogen; and n represents0, with 4-bromo-1,1,2-trifluoro-1-butene in the presence of an inertsolvent and optionally in the presence of an acid binder; or (b) forcompounds of formula (I) in which R¹ represents hydrogen; or alkyl thatis optionally substituted with halogen, hydroxy, alkoxy, alkylthio,alkylcarbonyloxy, haloalkyl-carbonyloxy, or cyano; R² representshydrogen or alkyl that is optionally substituted with alkoxy or halogen;and n represents 1 or 2, oxidizing a compound of the formula (Ia)

wherein R¹ represents hydrogen; or alkyl that is optionally substitutedwith halogen, hydroxy, alkoxy, alkylthio, alkylcarbonyloxy,haloalkylcarbonyloxy, or cyano; and R² represents hydrogen or alkyl thatis optionally substituted with alkoxy or halogen, in the presence of aninert solvent; or (c) for compounds of formula (I) in which R¹represents hydrogen or haloalkyl; R² represents halogen; and nrepresents 0, reacting a compound of the formula (Ib)

wherein R^(1b) represents hydrogen or alkyl; and R^(2b) representshydrogen, with a halogenating agent in the presence of an inert solvent;or (d) for compounds of formula (I) in which R¹ represents haloalkyl; R²represents hydrogen or haloalkyl; and n represents 0, reacting acompound of the formula (Ic)

wherein R^(1c) represents alkyl; and R^(2c) represents hydrogen oralkyl, with a halogenating agent in the presence of an inert solvent; or(e) for compounds of formula (I) in which R¹ represents halogen; R²represents hydrogen or alkyl; and n represents 0, reacting a compound ofthe formula (III)

wherein R^(2d) represents hydrogen or alkyl, with a halogenating agentin the presence of an inert solvent and optionally in the presence of anorganic base; or (f) for compounds of the formula (I) in which R¹represents alkylsulfonyloxy; R² represents hydrogen or alkyl; and nrepresents 0, reacting a compound of formula (III)

wherein R^(2d) represents hydrogen or alkyl, with a compound of theformula R^(1d)SO₂Cl  (IV) wherein R^(2d) represents alkyl, in thepresence of an inert solvent and optionally in the presence of aninorganic or organic base; or (g) for compounds of formula (I) in whichR¹ represents alkyl; R² represents alkoxycarbonyl; and n represents 0,reacting a compound of the formula (IV)

wherein R^(1c) represents alkyl; and R³ represents alkyl, with thioureato form a product that is then reacted with4-bromo-1,1,2-trifluoro-1-butene in the presence of an inert solvent; or(h) for compounds of formula (I) in which R¹ represents hydrogen; R²represents alkoxyalkyl; and n represents 0, reacting a compound of theformula (Id)

wherein R^(1e) represents hydrogen, with a compound of the formula (VI)R⁴—Br  (VI) wherein R⁴ represents alkoxyalkyl, in the presence of aninert solvent.
 7. A nematicidal composition comprising at least onetrifluorobutene of the formula (I) of claim 1 and one or more extenders.8. A process for combating nematodes comprising allowing an effectiveamount of a formulation or application form comprising 0.000001 to 100%by weight of a trifluorobutene of the formula (I) of claim 1 act onnematodes and/or the habitat of nematodes.